fix(icon): remove icons not supported by fabric
fix(icon): remove icons not supported by fabric

Office UI Fabric 2.x release removed a few icons that are no longer supported. This change updates the icon enum to reflect the current supported icons.

Closes #169.

andrewconnell/ng-officeuifabric,rolandoldengarm/ng-officeuifabric,jjczopek/ng-officeuifabric,johnmeilleur/ng-officeuifabric,s-KaiNet/ng-officeuifabric,andikrueger/ng-officeuifabric,andikrueger/ng-officeuifabric,andikrueger/ng-officeuifabric,ngOfficeUIFabric/ng-officeuifabric,rolandoldengarm/ng-officeuifabric,jjczopek/ng-officeuifabric,rolandoldengarm/ng-officeuifabric,andikrueger/ng-officeuifabric,andrewconnell/ng-officeuifabric,s-KaiNet/ng-officeuifabric,johnmeilleur/ng-officeuifabric,jjczopek/ng-officeuifabric,ngOfficeUIFabric/ng-officeuifabric,s-KaiNet/ng-officeuifabric,rolandoldengarm/ng-officeuifabric,andrewconnell/ng-officeuifabric,jjczopek/ng-officeuifabric,andrewconnell/ng-officeuifabric,rolandoldengarm/ng-officeuifabric,ngOfficeUIFabric/ng-officeuifabric,s-KaiNet/ng-officeuifabric,andikrueger/ng-officeuifabric,s-KaiNet/ng-officeuifabric,ngOfficeUIFabric/ng-officeuifabric,andrewconnell/ng-officeuifabric,ngOfficeUIFabric/ng-officeuifabric,jjczopek/ng-officeuifabric,johnmeilleur/ng-officeuifabric